1. Field of the Invention
The present invention relates to a clip for captivating a bolt in an assembly and more particularly relates to a banjo clip connecting a banjo block to a flow bolt that connects a brake line to a brake caliper.
2. Background Art
Fasteners are used to assemble parts together and attach them to a mounting surface. Frequently washers are used in conjunction with fasteners as part of an assembly to provide a broader bearing surface for the fastener head or nut and to inhibit loosening of the fastener as a result of part rotation or vibration. In some instances, washers may also serve as a fluid seal. One problem with separate washers and bolts is that assembly of them to other members requires manual dexterity and assembly time. Washers may become separated from the bolts especially when the washers are preassembled to the bolt prior to being assembled to another part.
One example of a part that uses washers for hydraulic sealing is a connector for connecting a brake line to a disc brake caliper. Copper washers are used to form a seal when a bolt secures the connector to the brake caliper. There are a wide variety of other assembly operations for which washers are required but make the assembly operation more difficult requiring a greater degree of manual dexterity in the assembly process.
Vehicle brakes generally include brake calipers to which brake fluid is ported through a brake line. One popular approach to brake design features brake calipers that are connected to the brake line by means of a flow bolt and banjo block. Such prior art brake systems include a flow bolt that is secured by means of a threaded connection to the brake caliper. The brake line is connected to a banjo block by means of a tube segment on which the brake line is received. The tube has an opening through which brake fluid is provided to an annular passageway through which fluid is ported to one or more ports in the flow bolt. Brake fluid passes through the port in the flow bolt and through an axially oriented passageway extending to the tip of the flow bolt where it provides fluid to the brake caliper mechanism. To minimize leakage, copper washers are generally provided on opposite axially facing sides of the banjo block thereby forming a high pressure seal on both sides of the banjo block when the flange head flow bolt is tightened.
One disadvantage of the above brake line to brake caliper fitting is that it involves a complicated vehicle assembly technique requiring multiple parts to be assembled on the line. The banjo block must be assembled to the brake line and the flow bolt must be inserted through the two washers and banjo block prior to assembling the flow bolt to the brake caliper. This approach requires additional parts that must be carried as inventory items. Pre-assembly of the washers, banjo block and flow bolt is not feasible with prior art systems because the parts could become separated from each other during shipment or storage.
Another disadvantage of the prior art system is that when the copper washers are press fit or coined to assemble them to the banjo block during press fitting or coining, metal shavings could be created that must be removed prior to assembly of the flow bolt to the brake caliper.
Crimping the copper washers to the bolt can also cause work hardening of the washers that may adversely affect the sealing performance of the washers. If a good seal is not maintained, brake fluid may leak from the flow bolt, resulting in warranty claims.
There is a need for an easy-to-assemble high pressure fluid connection between brake lines and brake calipers, or in other pressurized fluid connection applications. A modular flow bolt, banjo block, and banjo clip is needed that can simply be connected to the brake caliper and then connected to the brake line to simplify vehicle assembly operations.
There is also a need for an improved banjo block connector that does not require coining copper washers to the bolt.
In addition, there is a need for an indicator that can indicate if a flow bolt of a brake caliper has been improperly installed by over-tightening and that could indicate tampering with the flow bolt.
The above prior art system is improved and problems associated with the prior art are addressed by the present invention as summarized below.
According to one aspect of the present invention a banjo clip assembly is provided that includes a bolt having a head that is formed with a flange, a member having a central opening for receiving the bolt, and a banjo clip comprising an inner washer portion and an outer washer portion that are joined together by a bridging portion. The outer washer has a crimp tab that secures the banjo clip to the bolt when the bolt is inserted through the outer washer, the member, and inner washer. The crimp tab engages the flange and secures the bolt, the member, and the banjo clip together.
Other aspects relating to the banjo clip assembly that include the banjo clip may hold the bolt together with the member while the bolt is rotatable relative to the member and the banjo clip. In addition, the banjo clip may establish a fluid seal between one or both of the washers and the member when the bolt is tightened against the washers and the member. The fluid seal may be either a high pressure hydraulic fluid seal, a pneumatic seal, or other fluid seal. The banjo clip may be formed from a wide variety of materials including, but not limited to, copper, steel, aluminum, bronze or polymeric materials. The banjo clip assembly may be, for example, a brake caliper banjo, a component of a fuel injection system, or the like.
According to another aspect of the invention a fluid coupling is provided for connecting a brake line to a brake caliper on a vehicle brake system. The fluid coupling includes a flow bolt comprising a bolt having a fluid passageway connecting the brake line to the brake caliper. The flow bolt has a head that is formed with a flange. A banjo block having a brake line receptacle, a threaded opening and an internal passageway formed in the threaded opening that encircles the flow bolt. Brake fluid is free to flow from the brake line through the banjo block and the flow bolt to the brake caliper. The banjo clip may comprise an inner washer portion and an outer washer portion that are joined together by a bridging portion. The outer washer may have a crimp retainer. The fluid coupling as established by the flow bolt being inserted through the outer washer, the banjo block and the inner washer with the crimped retainer being formed over the flange of the flow bolt that secures the banjo clip to the flow bolt and the flow bolt to the banjo block.
According to another aspect of the invention the flow bolt may have a threaded shaft extending from the head to a distal end of the flow bolt. A central bore extends coaxially through a portion of the shaft. A radially extending bore is provided between the central bore and a fluid passage defined in the banjo block. The banjo block may have a tubing receptacle defining a fluid port and a threaded opening for receiving the flow bolt. An angular internal passageway is provided that is in fluid flow communication with the fluid port. The flow bolt may have a threaded shaft extending from its head to a distal end and a central bore extending coaxially through the portion of the shaft. A radially extending bore connects the central bore to the internal passageway defined in the banjo block.
According to another of the invention, a clip assembly is provided that secures together a bolt and fluid coupling member having a threaded opening for receiving the bolt. The clip comprises inner and outer washer portions that are joined by a bridging portion. The outer washer has a crimp tab formed thereon so that when the bolt is inserted through the outer washer, the fluid coupling and the inner washer, the crimp tab engages the flange to loosely secure the fluid coupling to the bolt.
According to other aspects relating to a clip assembly, the clip is adapted to hold the bolt together with the fluid coupling wherein the bolt is rotatable relative to the fluid coupling and clip. The clip may be required to create a fluid seal between at least one of the washers and the fluid coupling when the bolt is tightened against the washer and the fluid coupling. The fluid coupling may be a disc brake component part or a component of a fuel injection system.
According to another aspect of the present invention, a fluid coupling is provided for connecting a brake line to a brake caliper of a vehicle brake system. A flange head flow bolt comprising a bolt having a fluid passageway for connecting the brake line to the brake caliper for fluid flow communication. The flange head flow bolt has a head that is formed with a flange. A banjo block is provided that has a brake line receptacle, a threaded opening, and an internal passageway formed in the threaded opening that encircles the flange head flow bolt. Brake fluid flows from the brake line through the banjo block and the flange head flow bolt to the brake caliper. A banjo clip is provided that comprises an inner washer portion and an outer washer portion that are joined by a bridging portion. The outer washer is formed with a crimp retainer tab. The flange head flow bolt is inserted through the outer washer, the banjo block and the inner washer with the crimp retainer being formed over the flange of the flange head flow bolt to secure the flow bolt, banjo block, and banjo clip together.
These and other aspects and features of the invention will be better understood by one of ordinary skill in the art in view of the attached drawings and following detailed description of the best mode for practicing the invention.